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96-471: Both can be fitted with the Digital Modul R (DMR) digital back (discontinued in 2007 [1] ) and used as a digital camera making them the only 35 mm SLRs to take a user-installable digital back . The R8 was the first R-series camera to have no association with Minolta , being solely a Leica design and showing a clear stylistic change compared to prior bodies. Industrial designer Manfred Meinzer

192-431: A 35 mm digital SLR, but exposures of up to about an hour at room temperature and as long as 17 hours in extremely cold situations can remain noise-free on a digital camera back. In practice a 30-second exposure on a Sinar 75 evolution with a built-in fan-assisted Peltier -cooled CCD represents the state of the art for practical purposes . The resolution of digital camera backs (in 2017, up to 101 megapixels, IQ3 100)

288-439: A 49 MB sensor. There are alternative ways to create a high-resolution digital image without a digital back. If a high-resolution digital image is required, it can be achieved inexpensively without the use of a digital back by taking a large-format photograph on film and scanning the result; for best results a high-quality drum scanner is required. This can be used to create a much larger very high resolution computer file than

384-563: A GaAs p-n junction light emitter and an electrically isolated semiconductor photodetector. On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc-diffused p–n junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias . After establishing the priority of their work based on engineering notebooks predating submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs , and Lincoln Lab at MIT ,

480-401: A cable to a controlling computer that would store the images they took. Newer models added the ability to store the photos inside the back itself, and added displays so that the picture could be viewed on the back without requiring a separate computer. Virtually all backs can still be operated in tethered fashion, which allows convenient previewing of images on a large monitor by several people at

576-440: A camera back if fast operation and short exposures are not required. Another alternative is to take multiple smaller pictures and then stitch them together via image stitching . In this way very high-resolution images can be produced from a low-resolution sensor. This can be done with a smaller digital camera, such as a DSLR, and stitching sliding back adapters are available for large-format cameras. The process can be lengthy, and

672-461: A colored filter wheel inside the back rotated to take red, green, and blue exposures. Competition soon came to the new industry. MegaVision in 1992 introduced their T2 back, which was a similar product; it also was a 3-shot unit with a 4 MP square sensor. MegaVision had been making digital photography equipment based on video technology since 1984, and the T2 had live video preview. Phase One

768-469: A computer unnecessary so that the backs could be used wherever film can be used. While dedicated digital cameras suitable for advanced use are available, there are advantages in being able to use a film camera to take digital photographs. A single camera can be used for both film and digital photography. Cameras with features not available on digital cameras (e.g., view cameras ) can be used to make digital images. Digital backs which are used in place of

864-671: A current source of a battery or a pulse generator and with a comparison to a variant, pure, crystal in 1953. Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys in 1955. Braunstein observed infrared emission generated by simple diode structures using gallium antimonide (GaSb), GaAs, indium phosphide (InP), and silicon-germanium (SiGe) alloys at room temperature and at 77  kelvins . In 1957, Braunstein further demonstrated that

960-460: A drum scanner brought the projected cost over three years to about 80% of the cost of a digital back at the time. The digital back also had the advantage that the incremental cost of taking huge numbers of exposures was nil, while each 10 × 12.5 cm (4 × 5″) photograph cost over US$ 3. Both the scanned and the 39-megapixel images were noticeably better than images with a 22-megapixel back. An actual flatbed image scanner can be used as

1056-554: A glass window or lens to let the light out. Modern indicator LEDs are packed in transparent molded plastic cases, tubular or rectangular in shape, and often tinted to match the device color. Infrared devices may be dyed, to block visible light. More complex packages have been adapted for efficient heat dissipation in high-power LEDs . Surface-mounted LEDs further reduce the package size. LEDs intended for use with fiber optics cables may be provided with an optical connector. The first blue -violet LED, using magnesium-doped gallium nitride

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1152-568: A longer lifetime, improved physical robustness, smaller sizes, and faster switching. In exchange for these generally favorable attributes, disadvantages of LEDs include electrical limitations to low voltage and generally to DC (not AC) power, the inability to provide steady illumination from a pulsing DC or an AC electrical supply source, and a lesser maximum operating temperature and storage temperature. LEDs are transducers of electricity into light. They operate in reverse of photodiodes , which convert light into electricity. Electroluminescence as

1248-485: A loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup." In September 1961, while working at Texas Instruments in Dallas , Texas , James R. Biard and Gary Pittman discovered near-infrared (900 nm) light emission from a tunnel diode they had constructed on a GaAs substrate. By October 1961, they had demonstrated efficient light emission and signal coupling between

1344-557: A method for producing high-brightness blue LEDs using a new two-step process in 1991. In 2015, a US court ruled that three Taiwanese companies had infringed Moustakas's prior patent, and ordered them to pay licensing fees of not less than US$ 13 million. Two years later, in 1993, high-brightness blue LEDs were demonstrated by Shuji Nakamura of Nichia Corporation using a gallium nitride (GaN) growth process. These LEDs had efficiencies of 10%. In parallel, Isamu Akasaki and Hiroshi Amano of Nagoya University were working on developing

1440-523: A phenomenon was discovered in 1907 by the English experimenter Henry Joseph Round of Marconi Labs , using a crystal of silicon carbide and a cat's-whisker detector . Russian inventor Oleg Losev reported the creation of the first LED in 1927. His research was distributed in Soviet, German and British scientific journals, but no practical use was made of the discovery for several decades, partly due to

1536-574: A phosphor-silicon mixture on the LED using techniques such as jet dispensing, and allowing the solvents to evaporate, the LEDs are often tested, and placed on tapes for SMT placement equipment for use in LED light bulb production. Some "remote phosphor" LED light bulbs use a single plastic cover with YAG phosphor for one or several blue LEDs, instead of using phosphor coatings on single-chip white LEDs. Ce:YAG phosphors and epoxy in LEDs can degrade with use, and

1632-508: A red light-emitting diode. GaAsP was the basis for the first wave of commercial LEDs emitting visible light. It was mass produced by the Monsanto and Hewlett-Packard companies and used widely for displays in calculators and wrist watches. M. George Craford , a former graduate student of Holonyak, invented the first yellow LED and improved the brightness of red and red-orange LEDs by a factor of ten in 1972. In 1976, T. P. Pearsall designed

1728-480: A sensor similar to that used in most other digital cameras , a square or rectangular array of pixels. Backs are generally assumed to be non-scanning unless specified to be a scan back. Scanning backs operate more like an image scanner for paper: they have a linear array of sensors that is moved across the image area to scan the image one row of pixels at a time. Scanning backs are primarily used in large format view cameras . The first commercial digital camera back

1824-853: Is a device that attaches to the back of a camera in place of the traditional negative film holder and contains an electronic image sensor . This allows cameras that were designed to use film take digital photographs . These camera backs are generally expensive by consumer standards ( US$ 5,000 and up) and are primarily built to be attached on medium- and large-format cameras used by professional photographers . Two sensor back types are commonly used: single shot back (non-scanning) and scan back . Some backs, primarily older ones, require multiple exposures to capture an image; generally one each for red, green, and blue. These are called multi-shot or 3-shot backs. As technology advanced single-shot backs became more practical; by 2008 most backs manufactured were single-shot. Early backs had to be used tethered by

1920-550: Is difficult but desirable since it takes advantage of existing semiconductor manufacturing infrastructure. It allows for the wafer-level packaging of LED dies resulting in extremely small LED packages. GaN is often deposited using metalorganic vapour-phase epitaxy (MOCVD), and it also uses lift-off . Even though white light can be created using individual red, green and blue LEDs, this results in poor color rendering , since only three narrow bands of wavelengths of light are being emitted. The attainment of high efficiency blue LEDs

2016-492: Is difficult on silicon , while others, like the University of Cambridge, choose a multi-layer structure, in order to reduce (crystal) lattice mismatch and different thermal expansion ratios, to avoid cracking of the LED chip at high temperatures (e.g. during manufacturing), reduce heat generation and increase luminous efficiency. Sapphire substrate patterning can be carried out with nanoimprint lithography . GaN-on-Si

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2112-437: Is feasible with a single-shot digital back, and quality is high, though it has been argued that the resolution is not much better than a digitally photographed image. A detailed comparison in 2006 by a professional photographer of drum-scanned 10 × 12.5 cm (4 × 5″) images and digital 39-megapixel images on a medium-format camera found resolution very similar, with the scanned images slightly better. Color accuracy

2208-507: Is higher than any fixed sensor digital camera (in 2017, up to 51 megapixels, Hasselblad X1D). and captures more detail per pixel due to the omission of an anti-aliasing filter . Each pixel is also able to capture more dynamic range due to higher quality electronics and larger pixel pitch . The use of active cooling systems such as internal fans and Peltier effect electric cooling systems also contributes to image quality. The Sinar eXact creates images in excess of 1 GB in multi-shot mode from

2304-465: Is in the center of the shutter-speed dial and is threaded for a cable release . The optional Motor-Drive gives additional front and vertical-grip releases. The highly sophisticated metering system allows free choice of metering mode and exposure mode. By contrast, the earlier R4-R7 series lacked multi pattern metering and offered only pre-set combinations of metering and exposure. Three metering modes are offered: and five exposure modes: Mounted on

2400-794: Is more apparent with higher concentrations of Ce:YAG in phosphor-silicone mixtures, because the Ce:YAG decomposes with use. The output of LEDs can shift to yellow over time due to degradation of the silicone. There are several variants of Ce:YAG, and manufacturers in many cases do not reveal the exact composition of their Ce:YAG offerings. Several other phosphors are available for phosphor-converted LEDs to produce several colors such as red, which uses nitrosilicate phosphors, and many other kinds of phosphor materials exist for LEDs such as phosphors based on oxides, oxynitrides, oxyhalides, halides, nitrides, sulfides, quantum dots, and inorganic-organic hybrid semiconductors. A single LED can have several phosphors at

2496-438: Is much easier to manufacture a high-quality linear (one-dimensional) CCD array that has only a few thousand pixels than a two-dimensional CCD matrix that has millions, very high-resolution scanning CCD camera backs were available much earlier than their CCD matrix counterparts. For example, camera backs with a 7,000-pixel linear resolution—capable of scanning to relatively slowly produce pictures of about 40 MP—were available in

2592-599: Is perceived as white light, with improved color rendering compared to wavelengths from the blue LED/YAG phosphor combination. The first white LEDs were expensive and inefficient. The light output then increased exponentially . The latest research and development has been propagated by Japanese manufacturers such as Panasonic and Nichia , and by Korean and Chinese manufacturers such as Samsung , Solstice, Kingsun, Hoyol and others. This trend in increased output has been called Haitz's law after Roland Haitz. Light output and efficiency of blue and near-ultraviolet LEDs rose and

2688-657: Is substantially larger and heavier than the R4-R7 series cameras, being about a third heavier at 890g than the R7. This is partly explained by being built to take and balance the heavier zoom lenses in the Leica R lens range. The styling of the R8 proved controversial, some photographers consider it ugly and dubbed it the "Hunchback of Solms" ( Solms is the German town where Leica was headquartered;

2784-451: Is to use individual LEDs that emit three primary colors —red, green and blue—and then mix all the colors to form white light. The other is to use a phosphor material to convert monochromatic light from a blue or UV LED to broad-spectrum white light, similar to a fluorescent lamp . The yellow phosphor is cerium -doped YAG crystals suspended in the package or coated on the LED. This YAG phosphor causes white LEDs to appear yellow when off, and

2880-435: Is unsuited for moving subjects. There are also non-sliding options for stitching images together in various patterns using micro stepping of the image sensor and taking advantage of the gap between active pixel areas on the digital sensors. This stitching method is used to also give overlaid red green and blue pixel recording as well as increased resolution. By 2006 CCD matrix camera backs of 39 megapixels were available. using

2976-565: The Mamiya ZD . The imaging technology used in this camera is also available as a separate digital back, the ZD Back, which can be used with Mamiya's film cameras. Shortly after the product was announced, the company was sold. Pentax , for whose cameras digital backs are not available, sells a medium-format digital camera. Another trend is the release of new camera systems designed to tightly integrate with digital backs; this provides users with

Leica R8–R9 - Misplaced Pages Continue

3072-934: The Nobel Prize in Physics in 2014 for "the invention of efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources." In 1995, Alberto Barbieri at the Cardiff University Laboratory (GB) investigated the efficiency and reliability of high-brightness LEDs and demonstrated a "transparent contact" LED using indium tin oxide (ITO) on (AlGaInP/GaAs). In 2001 and 2002, processes for growing gallium nitride (GaN) LEDs on silicon were successfully demonstrated. In January 2012, Osram demonstrated high-power InGaN LEDs grown on silicon substrates commercially, and GaN-on-silicon LEDs are in production at Plessey Semiconductors . As of 2017, some manufacturers are using SiC as

3168-553: The U.S. patent office issued the two inventors the patent for the GaAs infrared light-emitting diode (U.S. Patent US3293513 ), the first practical LED. Immediately after filing the patent, Texas Instruments (TI) began a project to manufacture infrared diodes. In October 1962, TI announced the first commercial LED product (the SNX-100), which employed a pure GaAs crystal to emit an 890 nm light output. In October 1963, TI announced

3264-457: The human eye as a pure ( saturated ) color. Also unlike most lasers, its radiation is not spatially coherent , so it cannot approach the very high intensity characteristic of lasers . By selection of different semiconductor materials , single-color LEDs can be made that emit light in a narrow band of wavelengths from near-infrared through the visible spectrum and into the ultraviolet range. The required operating voltages of LEDs increase as

3360-451: The 3-subpixel model for digital displays. The technology uses a gallium nitride semiconductor that emits light of different frequencies modulated by voltage changes. A prototype display achieved a resolution of 6,800 PPI or 3k x 1.5k pixels. In a light-emitting diode, the recombination of electrons and electron holes in a semiconductor produces light (be it infrared, visible or UV), a process called " electroluminescence ". The wavelength of

3456-506: The CCD capabilities (macroscanning) with the arTec camera which creates a panoramic image with stitching technology. In addition to increased resolution, larger image sensors are becoming available; Kodak has produced a 50-megapixel CCD which is 49.1 × 36.85 mm (1.93 × 1.45″), approaching the size of a frame of 120 film (60 × 45 mm) and is twice the area of a 35 mm frame (36 × 24 mm), and over seventy times

3552-518: The Hy6. The Hy6 was also marketed by Leaf under their name and using their backs. The Sinar HY6 keeps the unique facilities of the rotating camera back and live image functionality. During this process, several product lines of digital backs were discontinued. Kodak stopped making their own backs in 2004, shortly before purchasing Leaf. Fuji had their own line of backs, but certainly only one product line will be produced by Fuji and Hasselblad together leaving

3648-655: The Kodak CCD and 33-megapixel Dalsa CCD in the Sinar 75 and in the Leaf Aptus 75 (6726 × 5040 pixels, with 7.2-micrometre-wide pixels). By 2008 several camera manufactures were developing larger camera backs based on the Kodak 50-megapixel CCD . Scanning backs are a narrower niche, used only for the highest-quality images with large-format cameras. Sinar continued their development of the step and repeat system of extending

3744-485: The Leica/Sinar group as the only European digital medium-format and view camera manufacturers. Sinar is now a subsidiary of Leica and are continuing developments of high technology digitisation with more spectrally accurate systems and optional image size output from a fixed sized cameraback for increased speed The early digital camera back market was dominated by scanning, rather than single-shot, models. Since it

3840-453: The R stepped cam may be used, but very early lenses fitted only with sloped cams (1 or 2 cam lenses) may damage the ROM contacts and should first be fitted with the stepped cam. Lens / camera combinations are as follows: Leica 1 cam, 2 cam, 3 cam, & R stepped cam lenses may be fitted with ROM contacts but as this entails removal of the original sloped cams they would then be incompatible with

3936-481: The R9 was reduced by 100g (to 790g) from the R8, achieved by switching to a magnesium casting for the top plate (formerly zinc alloy) and substituting aluminum for steel at the bottom plate's frame. Electronic changes included the ability to tune the sensitivity of matrix metering in steps of 0.1 EV independently of the other metering modes, and several improvements to the flash support. Metz's HSS (High Speed Sync) flash mode

Leica R8–R9 - Misplaced Pages Continue

4032-407: The R9; black remained available. Another external change was the addition of an LCD frame counter on the top plate between the wind lever and the shutter-speed dial. The mode selector dial gained a lock, after many R8 user complaints that it was too easily moved from the desired setting when handling the camera. The rear LCD display gained a backlight so it could be viewed in dim lighting. The mass of

4128-718: The Sinarcam shutter system. As of 2014 Phase One has a large market share with their own camera manufacturing and the IQ series digital backs that offer 80, 60.5 and 40MP resolution respectively. IQ180 and IQ160 both capture in full-frame 645 format. During the first decade of the twenty-first century the digital back market began to change and consolidate quickly. One trend was the displacement of medium-format film cameras were by digital single-lens reflex cameras based on smaller, 35 mm film cameras, which can offer high-quality results with no more expense than medium-format film gear. At

4224-539: The Valeo, and Jenoptik/Sinar had the 11 MP Sinarback 43. several vendors had 16 MP models; Kodak produced the US$ 15,000 16 MP Pro Back Plus using their own CCD, Imacon made the ixpress 96, Phase One had their H20 and Sinar continued its camera back development from the 22, 23h, 43h and issued the 44H which when mounted on a macroscan unit delivered an image of over 1 GB in size with live image focussing using

4320-551: The ability to use film, but is easier to use for digital work than a film camera with a less-integrated accessory digital back. Under pressure from digital camera back manufacturers, long-established medium-format SLR manufacturer Hasselblad eventually merged with back maker Imacon under the Hasselblad name. The post-merger Hasselblad worked with Fuji to develop a new line of cameras (Hasselblad's first in over 50 years) designed to closely integrate with digital backs, particularly

4416-470: The area of the typical 1/1.8″ (7.2 × 5.3 mm) sensor size used in point-and-shoot pocket cameras. Large-area CCDs are used by the several manufacturers of high-resolution photographic equipment. Other recent innovations are built-in LCD viewing screens and the inclusion of all processing within the camera back, with output in open DNG file format, as in the Sinar 65. The Pentacon Scan 7000 scanner camera

4512-800: The blending of the colors. Since LEDs have slightly different emission patterns, the color balance may change depending on the angle of view, even if the RGB sources are in a single package, so RGB diodes are seldom used to produce white lighting. Nonetheless, this method has many applications because of the flexibility of mixing different colors, and in principle, this mechanism also has higher quantum efficiency in producing white light. There are several types of multicolor white LEDs: di- , tri- , and tetrachromatic white LEDs. Several key factors that play among these different methods include color stability, color rendering capability, and luminous efficacy. Often, higher efficiency means lower color rendering, presenting

4608-1088: The cladding and quantum well layers for ultraviolet LEDs, but these devices have not yet reached the level of efficiency and technological maturity of InGaN/GaN blue/green devices. If unalloyed GaN is used in this case to form the active quantum well layers, the device emits near-ultraviolet light with a peak wavelength centred around 365 nm. Green LEDs manufactured from the InGaN/GaN system are far more efficient and brighter than green LEDs produced with non-nitride material systems, but practical devices still exhibit efficiency too low for high-brightness applications. With AlGaN and AlGaInN , even shorter wavelengths are achievable. Near-UV emitters at wavelengths around 360–395 nm are already cheap and often encountered, for example, as black light lamp replacements for inspection of anti- counterfeiting UV watermarks in documents and bank notes, and for UV curing . Substantially more expensive, shorter-wavelength diodes are commercially available for wavelengths down to 240 nm. As

4704-496: The company moved back to its original home town of Wetzlar in 2014). The size and bulk of the camera attracted much criticism although the R8/9 fitted with motor winder were almost exactly the same size and weight as the preceding R7 with motor winder. The R8 was without doubt the most complex camera Leica had ever constructed containing extensive electronics including a microprocessor, despite its manual operation bias, and in addition

4800-417: The cost of reliable devices fell. This led to relatively high-power white-light LEDs for illumination, which are replacing incandescent and fluorescent lighting. Experimental white LEDs were demonstrated in 2014 to produce 303 lumens per watt of electricity (lm/W); some can last up to 100,000 hours. Commercially available LEDs have an efficiency of up to 223 lm/W as of 2018. A previous record of 135 lm/W

4896-1075: The earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs , and in seven-segment displays . Later developments produced LEDs available in visible , ultraviolet (UV), and infrared wavelengths with high, low, or intermediate light output, for instance, white LEDs suitable for room and outdoor lighting. LEDs have also given rise to new types of displays and sensors, while their high switching rates are useful in advanced communications technology with applications as diverse as aviation lighting , fairy lights , strip lights , automotive headlamps , advertising, general lighting , traffic signals , camera flashes, lighted wallpaper , horticultural grow lights , and medical devices. LEDs have many advantages over incandescent light sources, including lower power consumption,

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4992-543: The emitted wavelengths become shorter (higher energy, red to blue), because of their increasing semiconductor band gap. Blue LEDs have an active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN, called cladding layers. By varying the relative In/Ga fraction in the InGaN quantum wells, the light emission can in theory be varied from violet to amber. Aluminium gallium nitride (AlGaN) of varying Al/Ga fraction can be used to manufacture

5088-496: The field of luminescence with research on radium . Hungarian Zoltán Bay together with György Szigeti patenting a lighting device in Hungary in 1939 based on silicon carbide, with an option on boron carbide, that emitted white, yellowish white, or greenish white depending on impurities present. Kurt Lehovec , Carl Accardo, and Edward Jamgochian explained these first LEDs in 1951 using an apparatus employing SiC crystals with

5184-612: The first commercial hemispherical LED, the SNX-110. In the 1960s, several laboratories focused on LEDs that would emit visible light. A particularly important device was demonstrated by Nick Holonyak on October 9, 1962, while he was working for General Electric in Syracuse, New York . The device used the semiconducting alloy gallium phosphide arsenide (GaAsP). It was the first semiconductor laser to emit visible light, albeit at low temperatures. At room temperature it still functioned as

5280-521: The first commercially available blue LED, based on the indirect bandgap semiconductor, silicon carbide (SiC). SiC LEDs had very low efficiency, no more than about 0.03%, but did emit in the blue portion of the visible light spectrum. In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices. Building upon this foundation, Theodore Moustakas at Boston University patented

5376-721: The first high-brightness, high-efficiency LEDs for optical fiber telecommunications by inventing new semiconductor materials specifically adapted to optical fiber transmission wavelengths. Until 1968, visible and infrared LEDs were extremely costly, on the order of US$ 200 per unit, and so had little practical use. The first commercial visible-wavelength LEDs used GaAsP semiconductors and were commonly used as replacements for incandescent and neon indicator lamps , and in seven-segment displays , first in expensive equipment such as laboratory and electronics test equipment, then later in such appliances as calculators, TVs, radios, telephones, as well as watches. The Hewlett-Packard company (HP)

5472-550: The former Imacon models. This meant that Shriro (owner of Hasselblad/Imacon) and Fuji could squeeze out other back makers, sending those manufacturers (and the remaining medium-format manufacturers) seeking their own partnerships. Mamiya announced a partnership with Phase One, which resulted in Phase One buying a major stake in Mamiya. Jenoptik commissioned Rollei to work with Sinar to develop their own tightly integrated platform,

5568-407: The important GaN deposition on sapphire substrates and the demonstration of p-type doping of GaN. This new development revolutionized LED lighting, making high-power blue light sources practical, leading to the development of technologies like Blu-ray . Nakamura was awarded the 2006 Millennium Technology Prize for his invention. Nakamura, Hiroshi Amano , and Isamu Akasaki were awarded

5664-417: The light depends on the energy band gap of the semiconductors used. Since these materials have a high index of refraction, design features of the devices such as special optical coatings and die shape are required to efficiently emit light. Unlike a laser , the light emitted from an LED is neither spectrally coherent nor even highly monochromatic . Its spectrum is sufficiently narrow that it appears to

5760-420: The light produced is engineered to suit the human eye. Because of metamerism , it is possible to have quite different spectra that appear white. The appearance of objects illuminated by that light may vary as the spectrum varies. This is the issue of color rendition, quite separate from color temperature. An orange or cyan object could appear with the wrong color and much darker as the LED or phosphor does not emit

5856-404: The location of the shutter speed dial lends itself to manual exposure control, as many Leica customers preferred this. In this it differs strongly from other contemporary SLRs, which were designed primarily for automatic operation. The top control wheels are sunk into the top plate, with knurled edges protruding at the front where they can easily be operated by the photographer's fingertips. The R8

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5952-631: The mid-1990s. Many earlier multi-shot backs could natively capture only grayscale images; color images were created by scanning three times through red, green, and blue filters which rotated into place. Early digital camera backs created more data than could be stored on the relatively small storage devices of the time that could be built into them, and had to be connected (tethered) to a computer during capture. Later, one-shot digital backs, which can work at all shutter speeds even on motorized medium-format cameras, were produced. Images are stored on fast high-capacity plug-in memory cards, making tethering to

6048-654: The normal film back are available for most medium and all large-format cameras with adaptors which can allow the same digital camera back to be used with several different cameras, allowing a photographer to choose a body/lens combination best suited for each application rather than using a body/lens system which represents a compromise of design to fit a variety of applications. Users with large investments in existing camera equipment can convert it to digital use, both saving money and allowing them to continue to use their preferred and familiar tools. Exposures longer than several minutes are obscured by image noise when captured with

6144-409: The original Leicaflex cameras. This was the first break in on-going compatibility of Leica reflex lenses. The R9 was an evolutionary step from the R8 and appears superficially very similar; enough so that some have opined that it should have been simply a Mark II of the R8, or in Leica nomenclature, an "R8.2".[2] The silver top-plate color available on the R8 was replaced by an 'Anthracite' color on

6240-463: The pentaprism housing. The shape is strongly asymmetrical, especially in plan view, with a bulged right handgrip and smaller, tapered left-hand side. Another goal was to improve the ergonomics and to place controls so they could be easily reached and operated without removing the eye from the viewfinder. Although the R8 is capable of fully automated exposure and (with the addition of the integrally-styled motor drive or winder) automated film transport,

6336-448: The phosphors, the Ce:YAG phosphor converts blue light to green and red (yellow) light, and the PFS phosphor converts blue light to red light. The color, emission spectrum or color temperature of white phosphor converted and other phosphor converted LEDs can be controlled by changing the concentration of several phosphors that form a phosphor blend used in an LED package. The 'whiteness' of

6432-599: The photosensitivity of microorganisms approximately matches the absorption spectrum of DNA , with a peak at about 260 nm, UV LED emitting at 250–270 nm are expected in prospective disinfection and sterilization devices. Recent research has shown that commercially available UVA LEDs (365 nm) are already effective disinfection and sterilization devices. UV-C wavelengths were obtained in laboratories using aluminium nitride (210 nm), boron nitride (215 nm) and diamond (235 nm). There are two primary ways of producing white light-emitting diodes. One

6528-421: The rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein "…had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier and played back by

6624-430: The same time digital workflow was increasingly easy. This is leading to the development of all-digital medium-format cameras which do not need separate digital backs. Bronica and Contax , formerly two of the largest medium-format camera makers, went out of business. Fuji ceased production of their 680 medium-format film cameras. Mamiya crossed the product line divide in 2004, announcing a medium-format digital camera,

6720-430: The same time, sophisticated control of camera functions, and convenient storage for the large image files produced. Modern high resolution backs that push the limits of data storage and transfer technology still are able to make use of a tethered configuration to offload gigabytes of data to cheaper external storage mediums such as hard drives, instead of the more expensive integrated flash memory. Non-scanning backs have

6816-480: The same time. Some LEDs use phosphors made of glass-ceramic or composite phosphor/glass materials. Alternatively, the LED chips themselves can be coated with a thin coating of phosphor-containing material, called a conformal coating. The temperature of the phosphor during operation and how it is applied limits the size of an LED die. Wafer-level packaged white LEDs allow for extremely small LEDs. In 2024, QPixel introduced as polychromatic LED that could replace

6912-439: The secondary mirror itself was a single cell for selective measurement and in the camera base was a five segment cell for integrated measurement with multi-pattern measurement. Using both provided six measurement areas. Switching of both metering mode and exposure mode was electronic. Flash pre-exposure measurement was provided allowing the camera's meter to measure manually controlled flash such as studio flash. Pre-flash measurement

7008-442: The semiconductor recombine with electron holes , releasing energy in the form of photons . The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962,

7104-408: The space between the crystals allow some blue light to pass through in LEDs with partial phosphor conversion. Alternatively, white LEDs may use other phosphors like manganese(IV)-doped potassium fluorosilicate (PFS) or other engineered phosphors. PFS assists in red light generation, and is used in conjunction with conventional Ce:YAG phosphor. In LEDs with PFS phosphor, some blue light passes through

7200-547: The subsequent device Pankove and Miller built, the first actual gallium nitride light-emitting diode, emitted green light. In 1974 the U.S. Patent Office awarded Maruska, Rhines, and Stanford professor David Stevenson a patent for their work in 1972 (U.S. Patent US3819974 A ). Today, magnesium-doping of gallium nitride remains the basis for all commercial blue LEDs and laser diodes . In the early 1970s, these devices were too dim for practical use, and research into gallium nitride devices slowed. In August 1989, Cree introduced

7296-480: The substrate for LED production, but sapphire is more common, as it has the most similar properties to that of gallium nitride, reducing the need for patterning the sapphire wafer (patterned wafers are known as epi wafers). Samsung , the University of Cambridge , and Toshiba are performing research into GaN on Si LEDs. Toshiba has stopped research, possibly due to low yields. Some opt for epitaxy , which

7392-569: The team at Fairchild led by optoelectronics pioneer Thomas Brandt to achieve the needed cost reductions. LED producers have continued to use these methods as of about 2009. The early red LEDs were bright enough for use as indicators, as the light output was not enough to illuminate an area. Readouts in calculators were so small that plastic lenses were built over each digit to make them legible. Later, other colors became widely available and appeared in appliances and equipment. Early LEDs were packaged in metal cases similar to those of transistors, with

7488-461: The very inefficient light-producing properties of silicon carbide, the semiconductor Losev used. In 1936, Georges Destriau observed that electroluminescence could be produced when zinc sulphide (ZnS) powder is suspended in an insulator and an alternating electrical field is applied to it. In his publications, Destriau often referred to luminescence as Losev-Light. Destriau worked in the laboratories of Madame Marie Curie , also an early pioneer in

7584-538: The wavelength it reflects. The best color rendition LEDs use a mix of phosphors, resulting in less efficiency and better color rendering. The first white light-emitting diodes (LEDs) were offered for sale in the autumn of 1996. Nichia made some of the first white LEDs which were based on blue LEDs with Ce:YAG phosphor. Ce:YAG is often grown using the Czochralski method . Mixing red, green, and blue sources to produce white light needs electronic circuits to control

7680-618: Was achieved by Nichia in 2010. Compared to incandescent bulbs, this is a huge increase in electrical efficiency, and even though LEDs are more expensive to purchase, overall lifetime cost is significantly cheaper than that of incandescent bulbs. The LED chip is encapsulated inside a small, plastic, white mold although sometimes an LED package can incorporate a reflector. It can be encapsulated using resin ( polyurethane -based), silicone, or epoxy containing (powdered) Cerium-doped YAG phosphor particles. The viscosity of phosphor-silicon mixtures must be carefully controlled. After application of

7776-431: Was always selective and in addition to automatic TTL flash measurement during exposure with suitable automatic flash units which was always full field using two small light cells either side of the main multi-pattern cell. Exposure compensation was available in all exposure modes. Program mode can be biased towards longer or shorter shutter speeds by using the shutter speed dial. Also in program mode automatic flash exposure

7872-406: Was built in a very modular fashion to integrate seamlessly with motor drive units and new backs such as the Digital Modul R. The shutter used was a Copal vertically running metal-leaf unit capable of speeds between 1/8000 and 32 seconds steplessly in automatic modes, or to 16 seconds in half- stop steps in manual mode, as well as Bulb . The flash X-sync speed is 1/250 sec. The shutter release

7968-509: Was chiefly responsible for the R8 design, along with a team of designers largely new to Leica or drawn from outside. The R8 was intended as a clean break from the previous generation of Leica R cameras, which had been developed in cooperation with Minolta . A key design goal was to evoke the Leica M and its smooth top plate; instead of a raised pentaprism as in previous R series cameras, the R8 has sloped "shoulders" that blend almost seamlessly into

8064-421: Was constructed using the Sinar view camera system with a Sinarcam 1 shutter system which provided control of the live image, and an adapter plate was made to use the backs with Hasselblad cameras. Driver software generally required the use of an Apple Macintosh to operate the cameras. These systems were complex and expensive. They used custom controller cards (known as the " SCSI taxi"), and were 3-shot backs;

8160-415: Was engaged in research and development (R&D) on practical LEDs between 1962 and 1968, by a research team under Howard C. Borden, Gerald P. Pighini at HP Associates and HP Labs . During this time HP collaborated with Monsanto Company on developing the first usable LED products. The first usable LED products were HP's LED display and Monsanto's LED indicator lamp , both launched in 1968. Monsanto

8256-683: Was founded in 1993, and by 1994 was selling their StudioKit scanning backs. In 1998 Phase One launched the Lightphase. which was the first one-shot back that could compete with film in terms of quality. Resolution was 6 MP and the physical size of the CCD was full-frame 35 mm, however the back was designed to be used on Hasselblad 500-series cameras. Other early industry entrants included Jenoptik who produced products in cooperation with Sinar, Dicomed (a scanning back maker which closed in 1999), Better Light (the most prominent scanning back maker), and Kigamo. By 2003, Leaf had an 11 MP model,

8352-502: Was fully controlled by the camera: off in daylight conditions, fill in flash with low light, full flash when dark. Normal flash synchronisation speed is 1/250s and with suitable flash units can be up to the camera's highest speed of 1/8000s. The viewfinder display was digital LED visible in any lighting. The same bayonet and stepped cam of earlier R cameras was used, but additional electrical contacts called "ROM Contacts" were added to convey lens focal length setting. Any lens fitted with

8448-580: Was improved, and AE lock was now possible in all automated modes. Leica sell a number of dedicated accessories for the R8 and R9. In addition to the Digital Modul R , these comprise the following: On Wednesday, 4 March 2009, Leica announced via the L-Newsletter that no further stock was available and production of the R series cameras and accessories had ended.[3] Collaboration with Minolta Digital back A digital camera back

8544-560: Was introduced at the photokina 2010 show in Cologne, Germany. Its resolution is 20,000 × 20,000 pixels (400 megapixels) in 48-bit color depth, and it is supplied with the SilverFast Archive Suite. One scanned exposure at this high image resolution might take 2 to 4 minutes. LED A light-emitting diode ( LED ) is a semiconductor device that emits light when current flows through it. Electrons in

8640-481: Was introduced by Leaf (now part of Phase One ) in 1991. The Leaf DCBI (Digital Camera Back I), nicknamed "The Brick", offered resolution of 4 megapixels (MP) in a 2048 × 2048 pixel format. The same CCD was used by Sinar in its equivalent sinarback. In 1994 Leaf introduced an improved model, the DCBII, which included a live-video view, and in 1998 they introduced the 6 MP Volare. A complete camera system

8736-433: Was made at Stanford University in 1972 by Herb Maruska and Wally Rhines , doctoral students in materials science and engineering. At the time Maruska was on leave from RCA Laboratories , where he collaborated with Jacques Pankove on related work. In 1971, the year after Maruska left for Stanford, his RCA colleagues Pankove and Ed Miller demonstrated the first blue electroluminescence from zinc-doped gallium nitride, though

8832-400: Was not compared as digital profiles for the digital back were not available, but the author was of the considered opinion that the digital camera would ultimately be more accurate. For sustained professional use the apparent cost advantage of scanning film was very much reduced on careful analysis; including expensive 10 × 12.5 cm (4 × 5″) film and processing and the cost of use of

8928-576: Was now supported, allowing fill flash at shutter speeds greater than the X-sync speed by the use of many repeated small flashes of the electronic flashgun. This mode could be used from 1/360 to the camera's shortest 1/8000 of a second shutter speed. Also improved was the use of fill-flash at slower shutter speeds and wider apertures, by enabling lower-power illumination modes on modern Metz equipment. The manual flash exposure compensation ability in Program mode

9024-443: Was quickly followed by the development of the first white LED . In this device a Y 3 Al 5 O 12 :Ce (known as " YAG " or Ce:YAG phosphor) cerium -doped phosphor coating produces yellow light through fluorescence . The combination of that yellow with remaining blue light appears white to the eye. Using different phosphors produces green and red light through fluorescence. The resulting mixture of red, green and blue

9120-571: Was the first intelligent LED display, and was a revolution in digital display technology, replacing the Nixie tube and becoming the basis for later LED displays. In the 1970s, commercially successful LED devices at less than five cents each were produced by Fairchild Optoelectronics. These devices employed compound semiconductor chips fabricated with the planar process (developed by Jean Hoerni , ). The combination of planar processing for chip fabrication and innovative packaging methods enabled

9216-484: Was the first organization to mass-produce visible LEDs, using Gallium arsenide phosphide (GaAsP) in 1968 to produce red LEDs suitable for indicators. Monsanto had previously offered to supply HP with GaAsP, but HP decided to grow its own GaAsP. In February 1969, Hewlett-Packard introduced the HP Model 5082-7000 Numeric Indicator, the first LED device to use integrated circuit (integrated LED circuit ) technology. It

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